The error I was getting was this:
Sep 23 13:07:14 webmonkey kernel: [675069.159578] npviewer.bin[6502]: segfault at ff99cd48 ip 00000000ff99cd48 sp 00000000ff9f059c error 14
The problem is fixed after upgrading the following packages to updates-proposed:
- libgl1-mesa-glx 7.4-0ubuntu3.3
- libgl1-mesa-dri 7.4-0ubuntu3.3
- libglu1-mesa 7.4-0ubuntu3.3
- mesa-utils 7.4-0ubuntu3.3

